The present invention relates to an automobile gear transmission driven by an internal combustion engine, and more particularly to a gear assembly adapted to the gear transmission for eliminating gear knocking noises in operation.
As is well known, gear knocking noises occur in the gear transmission due to inevitable fluctuation of the engine rotation and backlash of the assembled gears. Such gear knocking noises occur most noticeably during idling of the engine when the gear transmission is in neutral. For the purpose of eliminating the gear knocking noises, a gear assembly has been proposed which includes a pair of driving and driven gears permanently in meshing engagement with each other to provide a torque transmission therebetween, and an additional gear relatively rotatable at one side of either one of the gears and being permanently in meshing engagement with the other gear to rotate at a gear ratio different from that of the driving and driven gears, and in which the additional gear is resiliently in contact with one end face of the gear adjacent thereto to restrain a relative rotation between the driving and driven gears. In such a gear assembly as described, the additional gear does not act as a torque transmission gear. For this reason, the strength of the additional gear may be relatively low, while the additional gear is usually in contact with one end face of the toothed portion of the gear adjacent thereto. This results in unexpected defacement of the additional gear due to the presence of burrs on the toothed portion of the gear.